It would be helpful to read rule #9, Spreadsheets prior to reading this Rashi..

The table below presents an aligned extract of verses or verselets in Ex12-03:04, Ex12-21 Both verses/verselets discuss how groups form to eat the Passover lamb. The alignment justifies the Rashi comment that: The very general statement take flock for families stated by Moses corresponds to the three detailed statements given by God: (1) the family can comfortably consume one sheep; (2) There isn't enough meat in one sheep for the family which is too big but the family can divide into households each of which can comfortably consume one sheep (3) A household(or family) which consumed one sheep would leave over meat. In this case the house/family joins with neighbors until the group of neighbors can comfortably consume the entire sheep. Notice how God's three cases are summarized by Moses terse general case.

Verse	Text of Verse	Rashi comment
Ex12-03:04	Verses Ex12-03:04 outline three stages in determining groups of people for the Passover lamb. take a lamb per family ... [this is the ideal situation in which the number of people in the family can consume the entire lamb] a lamb per house [Suppose there are too many people in the family - that is, if the entire family got together for Passover and one lamb is divided among them then there would not be enough food for each person - in such a case we break up the family by houses and each house eats one lamb] and if the house is too small for a lamb...then he and his neighbor... [Suppose the number of the people in the house is too small; that is if the lamb would be divided among the people of the house and everyone ate as much as possible there would be leftovers; in such a case then multiple houses join]	The very general statement take flock for families stated by Moses corresponds to the three detailed statements given by God: (1) the family can comfortably consume one sheep; (2) There isn't enough meat in one sheep for the family which is too big but the family can divide into households each of which can comfortably consume one sheep (3) A household(or family) which consumed one sheep would leave over meat. In this case the house/family joins with neighbors until the group of neighbors can comfortably consume the entire sheep. Notice how God's three cases are summarized by Moses terse general case.
Ex12-21	Moses commanded the people take flock for your families.

Advanced Rashi: I have called this an alignment but I have only aligned one phrase. The Table below shows the alignment of the two passages - the command by God and the delivery of that command by Moses - in more detail. We have only concentrated on one row of this alignment. It is interesting how Moses summarized the three cases in one terse statement. Upon reviewing the alignment below we see many interesting differences some of which are not commented on by Rashi. As we have explained in this email newsletter it is very important to regard Rashi as sketching one or two illustrations of basic ideas which the teacher is expected to extend and generalize.

Ex12-03:07	Ex12-21:22
let them take	drag and take
(1) lamb per family (2) lamb per house (3) ...he and neighbors	flock per famailies
unblemished in its first year...watch it until the 14th and then slaguther it at noon	slaughter it as a Passover sacrifice
take its blood and place on two doorposts and overhead bar	take a hyssop bundle and dip in the blood in the bowl and touch the overhead bar and two doorposts